Anterior fontanelle

Anterior fontanelle - Definition

The anterior fontanelle is the large membranous area in the skull of fetus and newborns. It is one of the three fontanelles in human body, the others being posterior fontanelle and lateral fontanelle.

It is also referred to as:

Frontal fontanelle

Fonticulus anterior (Latin)

Soft spot (on the head of newborns)

Anterior fontanelle - Location

It can be found at the top of infantile head, at the junction or point of meeting of the two frontal and two parietal bones.

Anterior fontanelle - Size

It approximately measures 2.5 cm transversely and 4 cm antero-posteriorly. It is larger than the posterior fontanelle and resembles a diamond in shape.

Anterior fontanelle - Closure

The region usually ossifies and closes between 7 and 19 months of age. Like the posterior one, the closing of the anterior fontanelle generally occurs within the first year after birth. The closure is reported as delayed

if it remains open even after 2 years. During skull development, it is usually the last fontanelle that fuses. The fontanelle has an early closure in boys. It can have a premature closure in sufferers of Craniosynostosis, a congenital defect.

Anterior fontanelle - Functions

The structure lets the skull change its shape so that the fetus can easily pass through the birth canal. It also allows from brain expansion after birth.

Clinically, it is extremely important. The fontanelle generally tends to bulge when an infant is vomiting, crying or lying down. This resolves as soon as the child is calm or sitting upright. But a persistently bulged fontanelle is indicative of fluid accumulation inside the skull cavity or elevated pressure within the cranium. Any infant with a bulged fontanelle, and suffering from drowsiness and fever alongside, needs emergency medical care. Diagnosis involves CT scan, Lumbar puncture and MRI scans of the head.

Anterior fontanelle - Pictures

The images represent the appearance and position of the structure within the human body.